What does the term 'non-carcinogens' refer to?

The term 'non-carcinogens' specifically refers to substances that do not cause cancer. This definition focuses on the absence of cancer-causing properties in these materials, distinguishing them from carcinogens, which are known to promote cancer development in living tissues.

It is important to understand that while non-carcinogenic substances do not initiate or promote cancer, it does not imply that they are entirely free from any health risks. For instance, non-carcinogenic substances could still have other harmful effects on health or the environment, which is why they should not be automatically considered safe for all uses. This nuance is reflected in other options that mention general safety or unknown effects, which do not accurately define non-carcinogens. The clear focus on the cancer-related effects of substances is what makes option B the correct context for understanding non-carcinogens.